Packing flow restricting devices



Dec. 13, 1955 R. c. BAKER Y PACKING FLOW RESTRICTING DEVICES Filed DeC.15, 1952 ZEUBEN C, JgWER)I INVENTOR.

United States Patent O PACKING FLOW RESTRICITNG DEVICES Reuben C. Baker,Coalinga, Calif., assignor to Baker O il Tools, Inc., Los Angeles,Calif., a corporation of California Application December 13, 1952,Serial No. 325,869 12 Claims. (Cl. 166-204) 'I'he present inventionrelates to packing structures, and more particularly to the preventingof cold flow of flexible, pliable packing materials through substantialclearance spaces that might exist between the support for the packingstructure and the wall of a confining enclosure, such as a well casing,liner, or similar well conduit.

The packing structures of oil and gas well packers are usually made ofliexible, pliable materials, such as synthetic or natural rubber. Thereis a tendency for the packing material to cold ow through the clearancespace ordinarily provided between the packer and wall of the wellconduit in which the packer is run, when the packing structure is insealing engagement with the conduit wall, especially when the packingstructure is subjected to high pressures, high temperatures, or both.The cold owing through the clearance space may be of suicient extent tocompletely remove the packing material from its intended region ofsealing against the well conduit, thereby resulting in failure of theentire well packer.

An object of the present invention is to preclude the cold ilowing ofthe packing materials from their intended sealing regions when they aresubjected to high pressures, high temperatures, or both.

Another object of the invention is to provide an improved device forpreventing the cold flowing of a packing of the retrievable type, whichis expansible against the wall of a confining well conduit and which isalso retractable therefrom.

A further object of the invention is to provide a well packer embodyingan expansible and contractible device for preventing cold ow of packingmaterial through the clearance space between the packer and wall of aconining well conduit, the device being positive in its operation,strong and sturdy, and relatively economical to manufacture.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a combined side elevation and longitudinal section through aportion of a well packer embodying the invention, the packing structurebeing disclosed in retracted position;

Fig. 2 vis a fragmentary longitudinal section, on anenlarged scale, ofthe device disclosed in Fig. l, with the packing structure expandedagainst the wall of a confining well casing;

Fig. 3 is an exploded, isometric projection of the device `2,726,722Patented Dec. 13, 1955 ice for preventing cold owing of the rubber, orrubber-like, packing material.

The well packer disclosed in the drawings is generally of a known type,and may include an upper outer tubular body member 10 telescoped aroundan inner tubular body member 11. This inner tubular body member isslidable relatively along the inner surface of the outer tubular bodymember and may consist of several sections. As disclosed, it includes anupper section 12, which is threaded into a lower tubular body section13, that carries the ow preventing ring structure 14. This structure 14is engageable with one end, such as the lower end, of a packing sleeve15 of rubber or rubber-like material that surrounds the upper section 12of the inner tubular body 11. The upper end of the packing sleeve ispreferably secured to an upper abutment structure 16 attached to theouter tubular body 10. When the upper body 10 is telescoped downwardlyover the lower body 11, the packing sleeve 15 is foreshortened and iscompressed radially outward and inwardly into sealing engagement withboth the inner tubular body 11 and the wall of a well casing 17, orother coniining well conduit in which the apparatus is to be set. Whenexpanded outwardly, the packing sleeve 15 must bridge the substantialannular clearance space 18` normally existing between the well packerand the Wall of the surrounding Well conduit.

More speciiically, the apparatus disclosed in the drawings includes anupper abutment ring member 19 having an upper portion 20 threaded ontothe lower portion of the outer tubular body 10, the ring memberincluding an inwardly directed flange 21 extending across the lower endof the outer tubular body 10 for reception under an external iiange 22provided at the upper portion of the inner tubular body section 12. Itis preferred to tirmly secure the upper end of the rubber packing sleeve15 to the abutment ring 19. In the present instance, this isaccomplished by molding an upward extension 15a of the packing sleevewithin and to the inner surface of a tie ring 23 that is externallythreaded for threaded reception within a threaded lower portion 24 ofthe abutment ring 19. When the tie ring 23 is threaded into the abutmentring 19, the upper end of the packing sleeve 15 is firmly attached tothe abutment ring. However, the packing sleeve 15 and tie ring 23 arereadily disassembled from the abutment ring 19 by unthreading the tiering from the abutment ring.

As stated above, the other or lower end of the packing sleeve engagesthe lower abutment structure 14. This abutment structure is designed tooccupy a normal or initially retracted position when the apparatus is.being moved through the well casing 17, but is expandible out-- wardlyto bridge the clearance space 18 that usually exists between the wellpacker structure and the wall of the well casing, offering a barrier tothe cold ow of the packing sleeve material through this clearance space.closed, the lower end of the packing sleeve 15 engages a solid thrustand supporting ring 25 whose upper travel along the inner tubular body11 is limited by its engagement with a shoulder 26 formed on the tubularbody, this shoulder being disposed at the lower end of the cylindricalportion 27 of the body 11 encompassed by the packing sleeve. The ring 25has a depending or longitudinally extending boss 2S that provides arecess 29 with the remaining outer portion of the ring for the receptionof an inner split ring 30 which inherently tends to occupy a contractedor retracted position, with its generallyvcylindrical inner surface 31in engagement with the `cylind1 -ica l Y shoulder 32 defining theperiphery of the boss 28.

of which projects a ange portion 34. The upper end of As dis-V this ange`34 is slidable along the lower surface of the ring 25.' This innersplit ring 30 is disposed above and within an outer split ring 35 whichinherently tends to contract. This outer ring, in effect, is nestedwithin the inner ring 30, its longitudinally extending skirt or sleeve36 having its inner surface 37 slidably engaging the outer surface ofthe skirt or-sle'eve 33 ofthe inner ring 30. The outer ring 35 is alsoprovided with a flange portion 38 extending laterally outward from theskirt 36, and this tlange portion 38 is engageable with the lowersurface of the inner ring ange 34.

As disclosed in the drawings, the skirt portions 33, 36 of thetwo rings31), 35 are preferably cylindrical andthe eoengaging slidable surfacesVof the flange portions 34, 38 heretofore described are disposedgenerally at right angles tothe axis of the well packer. Y. `fThe lowerendsV 40 ofthe inner and outer skirts V33, 36

' This expander member is also provided with a tapered Surface 44 at'itsend parallel to the other tapered surface 41 and. engaging a taperedsurface 45 on the lower Vside o'f the outer ring flange 38. Y

For the purpose'of increasing the flexibility of the inner and outerrings 3i), 35, their ange portions 34 and 38 are provided .withamultiplicity of circumferentially spaced, generally radial slits:or-slots 46, 47 extending from the peripheries of the flangessubstantially to the respective skirt portions 33,. 36 of the rings.Thus, the

Vinner ring 30 has a large number of slits or slots 46, and

theY same is Atrue of the flange 38 of the outer expansibleandlcontractibie ring 35, because of the slots 47. Accordingly,. both ofthe rings 3), 35 may expand outwardly.

with. facility from their initial contracted or retracted Y positions.VThe gaps provided by the slots 46,. 47 allow the. ange material onVopposite sides of the slotsto move toward each other, tending to closethe slots. Y Y

The packer structure is mounted onthe body 11,V and the' partsV areinitially arranged in the position disclosed in Fig. vl. In this figure,the solid, or circumferentially continuous, thrust and supporting ring25 is in engagement with the shoulder 26, and this ring 25, in turn, hasits outwardly extending portion andV also the periphery 32 of Y its boss28 engaged by the inner expanding ring 36, which isY then in a retractedposition. The outer expanding ring 35 is also in retracted position.However, its split 50 is preferably `angularly oifset with respect tothe split 51 of therinner ring, to avoid alignment between the twosplits orI slots, which would provide al gap through theexpansibleabutrnent structure 14.` As an example, the splits 50, 51 ofthe rings may be substantially diametrically opposite one another. Inaddition, the two split ring members 30, 35 are so arranged that theirslits or slots 46, 47 are out of alignment with each other, the slits orslots beingl disposed, for example,.in the relative Y positionV shown inelevation in Fig. 1, being offset or staggered with respect to oneanother. When the parts are in retracted position, there isVarsubstantial gap 52 between the skirt 36 of the outer ring member 35and the skirt or sleeve portion 43 ofthe expander member 42, as clearlyshown in Fig. l'. In addition, the radial dimensions of the two anges34, 38 are. such that their peripheries lie on substantially the samecylindrical surface.

When the packing sleeve 15` is to be expanded, the lower tubular body 11 is held stationary by some other portion of the well packer, such as.a; lower setV of slips (not shown), that are movedintd anchoringengagement with` the wall offthe well casing, 1777.Y Since the inner 4tubular body 11 is now held stationary, the packing sleeve 15 can beexpanded by moving the outer tubular body 10 and its abutment ring .19downwardly toward the expander member 42 of the inner tubular body 11.Such downward movement is transmitted through the packing Y sleeve 15 tothe solid thrust ring 25,. This solid thrust ring then transmits themovement to the inner and oute'row preventing rings 3l),V 345, slidingthem downwardly along the tapered surfaces 41, 44 of the Vexpandermember 42 and in a radial outward direction intor rm engagement with thewall of the well conduit 17. When engaged with the wall ofthewellconduit, the split ring members 30,V

35 bridge the'annular space 18 between the solid ring 25 and the casingwall (Fig. 2'). Y

Y The inner and outer rings 30, 35 canexpand outwardly Vin view of thefact that they are split. This'expansionis allowed to occur, despite therelatively thick sections of their ilange'portions 34, 38, because ofthe provision of the radial slots 46, 47. During thev expansion, `andafter the full expansion of the two ringsinto. engagement with the wallof the well conduit 17, the .split portions 50, 51-

of the rings Vremain in their oset relation to each other,

and this is also true of thev staggered relation between i the radialflange slots 46, 47. .Y Y An increase in the downward force imposed, onthe outer tubular body 10 will now shift the upper abutment ring 19toward the expanded lower flow preventing ring structure 14,foreshortening thevr packing sleeve and expanding it radially into firmsealing engagement with they wall of the well conduit 17, asf well; asagainst the periphery of the inner tubular body '11 (see Fig. 2). If theendwise force; on the rubber packing sleeve is excessive,v then some ofthe packing` material willl ow around the exterior of the solid thrustring 25 and` through the'clearance space 18. VHowever, this rubberpacking materialV cannot pass beyond the flange 34 ofthe inner splitring i 30, since it is bridging the clearance space just referred to.Pressures imposed on the packing sleeve`15, suchas those that might bedue to thefhydraulic pressureV in the annulus 18 above the packingsleeve 'and between the outer tubular body 10 and the well conduit 17,may be' sorhigh (for example, it may be 8,000 p. s. i.) and the Vwelltemperatures may also be comparatively high (of the order of 300 degreesF.) that the packing material may even ow through the split 51 of theupper a'ngef 34. However, the packing material will then engage theflange 38 of the outer ring 35 therebelow, and cannot ow longitudinallyto any further extent.. Inraddition, Vthe radial slots 46, 47.V in theflanges will notpermit any ex.-V cessive flow of packing materialthereinto, since they, are.,

relatively narrow and the slots themselves close to a certain extent asa result of the outward expansion ofthe ring angcs 34, 38 intoengagement' with the wall of the well conduit 17.

When it is desired to retract the packing structure, theV outer tubularmember 10 is elevated with respect tothe inner tubular member'- 11, thepacking sleeve 15 inherently"V assumingitsv initial position. When theendwise force is removed from the thrust ringV 25 andthe split rings 30,35, then the split rings, due to` their inherentvcontractibility, willretract to their initial posit'ons, moving radially in-'- ward andupwardly along the expander surfaces 41, 44 back tothe positionsshowninFig. 1 The packing sleeve 15 and the cold flow preventingstructure'14` may againY be expanded and retracted a plurality of times,the'ilow preventing ring structure at all times bridging the annularclearance space 18 between the metallic packerpart 42 and the wallofthe. wellca'sin'g 17, to prevent cold flow ofthe packing materialthrough'` the Vclearance space;

The inventor claims:

l. in a packing structure: a pliant packing lada'pted to* be expandedlaterally; abutment means adjacentisaid p'ayck'-v ing anda having innerYandl outer: inclined exygsanrder"sur-v faces; and' a iiow .preventingring' device engaging said packing and abutment means, said deviceincluding an inner splitting engaging said inner expander surface,.a'nd

an outer split ring encompassing said inner ring and engaging said innerand outer expander surfaces.

2. in a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter inclined expander surfaces; and a flow preventing ring deviceengaging said packing and abutment means, said device including an innersplit ring having a skirt portion engaging said inner expander surfaceand a flange extending outwardly from said skirt portion, and an outersplit ring having a skirt portion encompassing said inner ring skirtportion and engaging said inner expander surface, said outer ring havinga flange extending outward from the outer ring skirt portion andengaging said outer expander surface.

3. in a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter inclined expander surfaces; and a ow preventing ring deviceengaging said packing and abutment means, said device including an innersplit ring having a skirt portion engaging said inner expander surfaceand a iiange extending outwardly from said skirt portion, and an outersplit ring having a skirt portion encompassing said inner ring skirtportion and engaging said inner expander surface, said outer ring havinga ange extending outward from the outer ring skirt portion and engagingsaid outer expander surface, said iianges being provided with aplurality of circumferentially spaced generally radial slots to increasethe iiexibility of the rings.

4. ln a packing structure as defined in claim l, wherein said ringsinherently tend to contract from outwardly expanded positions.

5. In a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter expander surfaces inclined laterally outward in a directionleading away from said packing; and a ow preventing device engaging saidpacking and abutment means, said device including an inner split ringhaving a skirt portion provided with an inclined end engaging said innerexpander surface and a ange extending outward from said skirt portion,and an outer split ring having a skirt portion encompassing said innerring skirt portion and provided with an inclined end engaging said innerexpander surface, said outer ring having a ange extending outward fromthe outer ring skirt portion and provided with an inclined surfaceengaging said outer expander surface.

6. in a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter expander surfaces inclined laterally outward in a directionleading away from said packing; and a liow preventing device engagingsaid packing and abutment means, said device including an inner splitring having a skirt portion provided with an inclined end engaging saidinner expander surface and a iiange extending outward from said skirtportion, and an outer split ring having a skirt portion encompassingsaid inner ring skirt portion and provided with an inclined end engagingsaid inner expander surface, said outer ring having a flange extendingoutward from the outer ring skirt portion and provided with an inclinedsurface engaging said outer expander surface, said anges being providedwith a plurality of circumferentially spaced generally radial slots toincrease the iiexibility of the rings.

7. In a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter inclined expander surfaces; a circumferentially continuous ringengaging said packing; an inner split ring engaging saidcircumferentially continuous ring and inner expander surface; and

an outer split ring encompassing said inner ring and engaging said innerand outer expander surfaces.

8. In a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter inclined expander surfaces; a circumferentially continuous ringengaging said packing; an inner split ring having a skirt portionengaging said inner expander surface and a iiange engaging saidcircumferentially continuous ring and extending outwardly from saidskirt portion; and an outer split ring having a skirt portionencompassing said inner ring skirt portion and engaging said innerexpander surface, said outer ring having a flange extending outward fromthe outer ring skirt portion and engaging said outer expander surface. A

9. In a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter expander surfaces inclined laterally outward in a directionleading away from said packing; a circumferentially continuous ringengaging said packing; an inner split ring having a skirt portionprovided with an inclined end engaging said inner expander surface and aange engaging said circumferentially continuous ring and extendingoutward from said skirt portion; and an outer split ring having a skirtportion encompassing the inner ring skirt portion and provided with aninclined end engaging said inner expander surface, said cuter ringhaving a ange extending outward from the outer ring skirt portion andprovided with an inclined surface engaging said outer expander surface.

l0. In a packing structure: a pliant packing adapted to be expandedlaterally; abutment means adjacent said packing and having inner andouter expander surfaces inclined laterally outward in a directionleading away from said packing; a circumferentially continuous ringengaging said packing; an inner split ring having a skirt portionprovided with an inclined end engaging said inner expander surface and aiiange engaging said circumferentially continuous ring and extendingoutward from said skirt portion; and an outer split ring having a skirtportion encompassing the inner ring skirt portion and provided with aninclined end engaging said inner expander surface, said outer ringhaving a iiange extending outward from the outer ring skirt portion andprovided with an inclined surface engaging said outer expander surface;said flanges being provided with a plurality of circumferentially spacedgenerally radial slots to increase the exibility of the rings.

11. In a packing structure: a pliant packing; a threaded ringsurrounding and molded to a portion of said packing, said portion beingdisposed interiorly of said ring; and an abutment member threadedlyreceiving said ring while engaging said packing.

12. in a packing structure: a pliant packing having a terminal portionand an adjacent portion spaced longitudinally from the end of saidterminal portion and having a greater external diameter than theexternal diameter of said terminal portion; a threaded ring surroundingand molded to said terminal portion, said terminal portion beingdisposed interiorly of said ring; and an abutment member threadedlyreceiving said ring while engaging the end of said terminal portion andthe end of said adjacent portion.

References Cited in the file of this patent UNITED STATES PATENTS2,368,928 King Feb. 6, 1945 2,555,647 King .lune 5, 1951 2,603,294Barnes July 15, 1952 2,604,946 Sweet July 29, 1952

